By LISA STIFFLER, P-I REPORTER

Published 10:00 pm, Tuesday, February 26, 2008

You may turn up your nose at farmed Atlantic salmon or shrimp raised in ponds in China if you're searching for wholesome, safe foods. But do you eschew fish pulled from a remote lake in a U.S. national park?

Maybe so if you're concerned about eating elevated levels of mercury and chemical flame retardants.

Some trout from secluded lakes in Olympic and Mount Rainier national parks were so polluted they reached unsafe levels for routine human consumption, according to a study out Tuesday.

The six-year investigation looked at pollution in air, water, sediment, lichen, conifer needles and fish in eight Western parks from Alaska to California.

Because the locations are rarely visited by people, the prime source of the pollution is from the air. Contamination from pesticides and flame retardants is believed to have more local sources, whereas the origins of mercury pollution are regional and global.

Mercury levels in some fish from Olympic National Park were some of the highest measured in the study, exceeding the 185 parts per billion standard that triggers warnings for people. The concentrations were well into the danger zone for wildlife that eat fish, including birds called kingfishers, otters and mink.

The government agency and university scientists were unsure of the precise source of the heavy metal. Some thought international sources were most likely -- coal plants in China and mining operations in South Africa -- while others thought local power plants including the TransAlta coal plant in Chehalis bore some of the blame.

There also are natural releases of mercury, such as volcanic eruptions and wildfires, though human activity contributes to up to two-thirds of the pollution globally.

Fish caught at Mount Rainier's Golden Lake also were contaminated with mercury and had the highest amounts of flame retardants called polybrominated diphenyl ethers, or PBDEs.

The PBDEs probably came from Seattle and other urban areas, Landers said. The chemicals are added to electronics, upholstered furniture, televisions and other consumer goods. They escape into the atmosphere as the products break down. Washington state was the first to pass a limited ban on PBDEs last year.

The long two-volume report, called the "Western Airborne Contaminants Assessment Project," was released by the National Park Service, though some of the authors published results in peer-reviewed journals. In addition to the eight main sites, data were collected at 12 secondary locations, including Washington's North Cascades.

Among the report's more surprising results were signs that some male fish were "feminized." For years researchers have linked female egg proteins in male fish with the presence of obvious estrogen sources, such as birth control in sewage waste. In the park study, the protein was found in some of the fish with the highest levels of chemicals that can mimic hormones -- including PBDEs.

The scientists also found pesticides and other industrial chemicals that were banned 20 or 30 years ago. Some are slow to break down in the environment and seem to circulate from the soil into the air and water and into organisms.